Field of the Invention
The invention relates to a signal processing apparatus and more particularly relates to a voice signal processing apparatus and a voice signal processing method.
Description of Related Art
The multi-frequency band WDRC (wide dynamic range compression) technology is extensively used in the field of hearing aids. Wide dynamic range compression is mainly to improve the loudness gain for a voice signal with low loudness to facilitate recognition as well as reduce the loudness gain for a voice signal with high loudness to avoid generating a loud voice that causes discomfort. The general multi-frequency band WDRC is to process the voice signal of each frequency band independently, and the WDRC curve of each frequency band is determined by the hearing test subject to individual needs. When the WDRC processing is performed on an input voice signal, the loudness of the output voice signal of each frequency band is determined respectively by the corresponding wide dynamic range compression curve with reference to the loudness detection result of the input voice signal of each frequency band. Such processing can enhance the loudness of the output voice signal. However, if the loudness gain corresponding to the loudness of the noise signal is larger, the signal-to-noise ratio may drop and cause low recognition of the output voice signal.